Compressor makes a knocking sound and then dies.

(Ma)

porter cable cffn250n air compressor

I have a porter cable pancake compressor for about 10 yrs. I turned it on the other day and it sounded like something was stuck knocking in the fan or a bearing was loose. Now when I turn it on it runs for a few seconds and then dyes. Compressor is not used regularly and mostly for light jobs, looks brand new still.

Comments for Compressor makes a knocking sound and then dies.

bill thank you for your time and thoughts. I'm a novice with these things. I took the cover off last night and it looks like I ripped the belt. Half the rubber was flapping around which explains the knocking. I really appreciate you spending the time to address my question. Best regards.

Oct 15, 2014

Model and imageby: Bill

Mike, I've found an image for what I think is your Porter Cable air compressor.

It's a pretty basic model.

When you pull the cover off, if you don't see anything out of whack, then run the compressor with the shroud off and see if you can pinpoint the source of the knocking.

Bill

Oct 15, 2014

Model infoby: Mike

Thanks bill! is model cffn250n 135 psi. I hope to pull the cover off tonight and have a look and see if I can identify anything out of whack. .

Oct 14, 2014

Knockingby: Bill

Since I don't have the model number I cannot find out if your Porter Cable air compressor is lubricated or not.

If it is oil lubricated, is the oil sump full?

If it's not, one thing that comes to mind when a compressor is knocking is the piston itself. It may have seals so badly worn that the piston is knocking in the cylinder... or...

It could be a number of things.

That the compressor dies after it runs for a bit suggests that the motor is going off on thermal overload, and that suggests increased load on the motor, and that could be mechanical - as in the piston issue I noted above.

Certainly, if you haven't done so, pull the cover off the pump area and have a look to see if anything's loose in the linkage between the motor and the cylinder.